The whole universe? Gotta go with the god-like heroes:
From DC:
SUPERMAN (insert John Williams theme here)
GREEN LANTERN (Hal Jordan, cause it's his frigging job)
CAPTAIN MARVEL (pre-New 52 non-douchebag version)
WONDER WOMAN (pre-bats vs supes non model waif version)
DR. FATE (again, his frigging job)
From Marvel:
CAPTAIN MARVEL (Mar-vell)
MS. MARVEL (Carol Danvers, in case the gods whine "why aren't you using Carol Danvers Capt. Marvel??")
CAPTAIN UNIVERSE (cause all you need is a warm body)
THE FANTASTIC FOUR (not including any crap version committed to celluloid thus far)
THOR
HERCULES (just to throw in a couple of demi-gods)
THE ETERNALS (all of 'em. I want an army ready if I need one.)
THE INHUMANS (see above)
CAPTAIN AMERICA (to be field general)
Epic:
DREADSTAR AND COMPANY (Vanth helped destroy a galaxy...he can help save the universe.)
Continuity Graphic:
CAPTAIN BUCKY O'HARE (and the Righteous indignation shall be my flagship)